WELLHEAD STUFFING BOX Russian patent published in 2023 - IPC E21B33/03 F16J15/18 

FIELD: seals.

SUBSTANCE: wellhead stuffing box is declared. The wellhead stuffing box comprises a body, an upper fixed main sealing unit and a lower backup sealing unit. The assemblies include sealing elements placed in cups with a central axial hole and pressure rings with a stop. The lower sealing assembly is configured for limited axial movement between the body stop and the upper sealing assembly to form a variable volume chamber. The chamber is equipped in its upper part with a check valve and a plug placed in the radial openings of the housing. The housing is provided with a cover configured for interaction with the pressure ring of the upper sealing unit. The body below the radial holes is provided with an upper stop. The upper and lower sealing units are equipped with spacer bushings spring-loaded relative to the cups, interacting with the pressure disks and configured for interacting with the cover and the upper stop of the body, respectively, at the upper position of the lower sealing unit.

EFFECT: increased life of the sealing units of the wellhead stuffing box.

2 cl, 3 dwg